Compressor.



" time JOHN STUMPF, OF BERLIN, GERMANY.`

COMPRESSOR.

SPECIFICATION forming part 0f Letters :Patent NO. 706,276, dated. August 5, 1902.

Application filed May 9,1901. Serial No. 59,514. (No model.)

To @ZZ whom, it may concern'.-

Beit known that I, JOHN STUMPF, a subject of the Emperor of Germany, residing at Berlin, Germany, have invented a new and useful Improvement in Compressors,of which the following is a specification.

My object is to provide an improved steamactuated air or gas compressor adapted more especially for use where economy in space and simplicity in construction are necessary or desirable.

Referring to the drawings, Figure 1 is a sectional elevation of a compressor constructed in accordance with my improvement in the preferred form, and Fig. 2 a similar view of a modication. l

A is a cylinder provided with the heads B C, and D is a piston working in the cylinder. Extending through the center or the cylinderhead C is an opening a, closed at its outer or lower end by a hollow plug b. The opening ct and plug together form a valve-chamber surrounded towardits lower side with asteaminlet port c, communicating with the steaminduction pipe E, and also surrounded above the port c by a steam-outlet port d, commu# eating with a steam-eduction pipe F; In the steam-chamber o is a' slide-valve G, having the annular steam-passage e extending from its upper face down to a'point about'midway between its ends and then outward through the side of the valve, as shown.. Therpassage e may be a series of small cored openings for convenience of construction. At the upper side of the valve is an annular shoulder f, adapted in the rise of the valve to abut against an annular stop or shoulder f in the pistonhead, and the valve is formed at its outer side with an annular shoulder g to strike a stop g', formed by the end of the plug b, to limit the downward movement of the valve.

The piston Din the preferred construction in Fig. lis formed with an upwardly-entending hollow stem D', closed at its upper end by a screw or plug 72,. On the valve G is a solid vertical stem G, extending at its upper end in the chamber h of the stem D. On the stem G' is a shouldered head t', adapted to be engaged by the plug 7i, in the downstroke of the piston, as hereinafter described, and

adapted to be engaged by an annular shoulf der h2 at the lower end of the chamber 71, in

the upstroke of the piston. Rising from the center of the piston-head B is a tubular chamber H, in which the stem D tits and slides. At its upper end the chamber I-I communicates through a pipe H'vwith the steamn inductionchamber o, or it may communicate with the steam-pipe E. In the head B is an air or gasinlet port 7e, provided with an inwardly-opening check-valve 7c. Also in the head B is an` air or gas outlet port Z, provided with an outwardlyopening checkvalve Z. In practice the port Z would communicate through a pipe (not shown) with a reservoir or the like, and particularly if the compressor is to be employed for compressing -gastheport lo would communicate through VThe upperrendof the piston-stem D is eX- posed at all times to the pressure of steam in the chamber I-I, and the piston is raised, as

described, against the resistance of the steampressure upon the comparatively small area of the end of said stem. Thus when the steam is shut off by the slide-valve and the outletport open the pressure of the steam in the chamber H forces the Vpiston down until the head i of the stem G is engaged bythe plug h and forced down to slide the valve G to close the port d and open the port c. In the downward movement of the piston air or gas is sucked in through the port 7c, and in the upward movement of the piston the air or gas is compressed and forced out through the port l.,

The cylinder A operates both as the steamcylinder and aeriformiluid-compression cylinder, and but one piston is employed both for receiving the steam-pressure and for performing the compression.

Around the cylinder-wall is an outer concentric cylinder-wall I, forming a dead-air or ICO ' with its steam-supplying means.

.insulating space 'm around the cylinder-chamber. l'.lhis air-jacket or insulating-space has the eiect of preventing radiation to any material extent of heat from the cylinder-Wall. When the air or gas is compressed against a high back pressure, the heat generated by the compression may be greater than that of the steam, particularly when the latter is supplied at a comparatively low pressure. 'Ihe piston D, particularly under these circumstances, and the wall'of the chamber A form heat-conductors which operate' to transfer the excessive heat generatedin the aeriform fluid by compression to the steam entering the cylinder. The eect of this transfer of heat is to prevent to a more or less material extent the condensation of the steam, with consequent saving of steam. It has been found in practice that this transfer of heat, especially when compression is comparatively high and steampressure comparatively low, eectsa very material saving in the operation of the compressor, which of course is much to be desired.

In the construction shown in Fig. 2 a Weighted piston D is substituted for the construction involving the stem D and chamber H (Shown in Fig. 1.) The piston D is thickened or otherwise constructed to give it comparatively great weight, which will be sufficient in operation to cause the piston to descend quickly when the steam-induction port is closed and the steam-eduction port open. The increased thickness of the piston increases its storing means for heat transferred from the compression to the steam side thereof. The stem G' of the slide-valve moves at its upper end in a central bore or chamber h of the piston, corresponding with the chamber h in Fig. l, and the valve is actuated to open and close the steam-ports in practically the same Way as in the preferred construction. area exposed to steam in the chamber H, Fig. l, and the weighted piston in Fig. 2 contribute an ever-present piston-returning counter force to the action of the live steam when it raises the piston.

While I prefer to construct my improvements in the manner shown and described, it will be obvious vto any one skilled in the art that they may be variously modified in the matter of details of construction Without departing from the spirit of my invention as defined by the claim.

What I claim as new, and desire to secure by Letters Patent, is-

In a steam -actuated aeriform-fluid com- Both the pressor, the combination of a single cylinder forming both the steam chamber and the compression-chamber, a piston working in the cylinder exposed on one side to the steam and performing on its other side the Work of compression, a steam inlet and outlet slidevalve, means for positively moving the valve consisting of a stem connected at one end to the valve and provided at its other end with a shoulder, said stein being movable in a chamber in the piston, ashoulder at the lower end of the chamber adapted in the upward movement of the piston to engage the shoulder on the stem to close the valve, a shoulder at the upper end of the chamber adapted in the downward movement of the piston to engage the end of the stem to open the valve, and piston returning means opposing the force of the piston-moving means.

JOHN STUMPF.

In presence of-ru THEoDoR HOLSCHER, ToH. HoLsoHER. 

